Overload circuit-breaker.



C. T. EVANS.

OVERLOAD CIRCUIT BREAKER. APPLICATION FILED JUNE 28. I917.

Patented July 9, 1918;

2 SHEETS-SHEET l.

C. T EVANS. OVERLOAD CIRCUIT BREAKER.

APPLICATION FILED JUNE 28. 1911.

Patented July 9, 1918, 2 SHEETS-SHEET 2 CLARENCE I. EVAN S, 015MILWAUKEE, WISCONSIN, ASSIGNOR TO THE CUTLEfiHAMMER MFG. (10., FMILWAUKEE, WISCONSIN, A CORPORATION OF WISCONSIN.

OVERLOAD CIRCUIT- BREAKER.

Specification .01 Letters Eatent.

Patented July a, rare.

Application filed June 28, 191?. Serial No. 177,454..

. To all whom it may concern:

Be it known that I, CLARENCE T. EVANS, a citizen of the United States,residing at Milwaukee, in the county of Milwaukee and State ofWisconsin, have invented new and useful Improvements in OverloadCircuit- Breakers, of which the following is a full, clear, concise, andexact description, reference being bad to the accompanying draw-. ing,forming a part of this specification.

This invention relates to overload circuit breakers and moreparticularly to those which are non-closable on overload.

Among the objects of the invention is to provide a circuit breaker ofthe character stated having few and rugged parts compactly arranged forinclosed mounting and also arranged for. quick and positive response tooverloads.

A further object is to provide a circuit breaker of the aforesaidcharacter adapted to insure a wide and substantially uniform separationof its contacts when tripped either manually or by overloads.

Other objects and advantages will hereinafter appear.

In the accompanying drawing Figure 1 is a front elevational view of anembodiment of the invention;

Fig. 2 is a vertical sectional view substantially on line aa of Fig. 1;

Fig. 3 is a similar view showing certain parts in altered relation;while,

Fig. 1 is a side elevational view showing details of the trippingmechanism.

Referring to the drawing, the same illustrates a double pole circuitbreaker comprising a pair of fixed contacts 1 and 2 mounted side by sidefor engagement by a pair of movable contacts 8, 1, the latter beingcarried in spaced relation upon a switch arm 5 which is pivoted at 6upon a manually op erable and lockable lever 7. A spring 8 fixed betweensaid arm 5 and a part of said lever serves to bias the former towardopen circuit position in all positions of the latter, while an extension9 of said arm is nor-v mally engaged by a pivoted latch 10 forrestraining such movement thereof, subject, however, to release of saidlatch by a tripping coil 11 upon overload. The lever7 is pivotedmedially upon 'a fixed supporting bracket 12 and operable for openingand closing the switch by means of a handle 13 acting through a toggleconnection, all of the aforementioned parts being carried in suitableoperative relation upon an insulating panel 15. I

The fixed contacts are secured upon the panel 15 by means of studs 16projecting therefrom, while the movable contacts are resiliently securedin insulated relation, and in a known manner, to the upper outerportions of the switch arm 5 for movement therewith, the respectivepairs of contacts being separated 'by an insulating barrier 17.

Said switch arm preferably comprises an integral sheet met-a1 stampingincluding a substantially flat body portion 18, an angularly extendingportion 19, and a pair of spaced downwardly projecting lugs 20, one ofsaid lugs being continued andofiset to form the latch engaging extension9.

The lever 7 also comprises an integral sheet metal stamping having abody portion 21 and parallel side portions 22, the upper end of saidbody portion being separated from said side portions and bent backwardlytherefrom, and the lower ends of said side portions projecting beyondsaid body portion as shown.

The lever 7 is pivotally mounted between a pair of arms 23 of thebracket 12 by means of a pin 24 extending therethrough and through theside portions 22 of said lever, the upper ends of said side portionsextending between the lugs 20 of the switch arm 5 for pivotal connectiontherewith by means of a pin 25. .The spring 8 is secured between thebent upper end of the lever 7 and the body of the arm 5 whileoutwardmove-- being pivotally mounted at 30 between extensions 31 of thebracket 12', while a fixed stop 32 serves to limit displacement of thetoggle in an upward direction. A shaft 33 carrying the handle 13 isrigidly secured to the link 29 for manual operation of the switch.

The latch 10 is pivotally mounted upon the'bracket 12 in relation asnormally to engage a roller 34 carriedby the switch arm extension 9,said latch being provided 1 with calibrating means 39 of knownconstruction. Y

In practice, the various contacts and'the tripping coil are providedwith the usual circuit connections, and the entire mechanism is inclosedwithin a rectangular casing 10 secured to thepanel15 and of suitable di-I v mensions to permit complete opening move- 'ment of the contacts 3,4:- and flexing of the toggle connection, the space require by theremaining portions of the switch being within the limits thusestablished.- The operating handle 13 is preferably located outside thecasing, as shown.

The switch may be operated manually by actuation of the handle 13 toflex the toggle connection downwardly, in which case the switch arm 5and the upper portion of the lever 77 move substantially as a unit aboutthe axis 24. Upon the occurrence of an overload the tripping lever 37moves upwardly to trip the latch 10 whereupon the switch arm 5 pivotsabout the axis 25 to open position under the action of the spring 8, the

lever 7 and other associated parts remaining stationary during suchoperation.

0 close the switch following such opening, the operating handle 13 isfirst moved to flex the toggle connection thereby forcing the upper end,of the lever 7 outwardly against the tension of the spring 8. Theswitch arm 5 is prevented from following such movement of the lever 7 bythe engagement of the rollers 26 against the fixed stop surfaces 27whereby said switch arm pivots about the axis 25 until the roller 34 isengaged by the latch 10. Following such preparatory movement, the switchis closed by reverse movement of the operating handle, wh ch serves tostraighten the toggle connection for swinging the lower end of the lever7 outwardly about the axis 24. The switch arm 5, being constrained bythe latch 10 to follow the movement of said leyer, 1s thusiswunginwardly to circuit closing position.

hould a condition of overload exist upon such closure of the switch, thecoil 11 is at once energized to trip the latch, whereupon by LettersPatent is:

the switch arm 5 immediately moves about the axis 25 to open position inresponse to its bias, whereby permanent closureofthe,

switch under such conditions is prevented.

The spring 8 being located between the lever 7 and the switch arm 5 iscompressed during movement of the handle 13 preparatory to closure ofthe switch and therefore not essential to successful operation of theswitch. The stops 27 are so spaced from the rollers 26 and the otherswitch parts are so proportioned as to insure substantially the sameseparation of the contacts upon overload opening as upon opening throughthe manually controlled means.

What I claim as new and desire to secure 1. In a circuit breaker, thecombination with relatively movable contacts, of a pivoted lever, aswitch arm carrying certain of said contacts, said arm being pivotallymounted upon said lever for movement therewith and being biased. to moverelatively thereto for disengagement of said contacts,electromagnetically controlled means for'restraining said switch armagainst such movement subject to release under abnormal electricalconditions and means for actuatwith relatively movable contacts, 'of apivoted lever, a switch arm carrying certain of said contacts, said armbeing pivotally mounted upon said lever for movement therewith and beingbiased to move relatively thereto for disengagement of said contacts, anelectromagnetically controlled latch pivoted at a fixed point andadapted ing said lever, said means bein operable for to restrain'saidarm against such movement subject to release under abnormal electricalconditions and means for actuating said lever, said means being operablefor moving said arm to position-of restraint following movement thereofin response to its bias and thereafter operable for moving said arm toclosed circuit position during restraint of said arm by said latch.

3. In a circuit'breaker, in combination, a pivotally mounted lever, aswitch arm mounted thereon for joint movement therewith and movementrelative thereto, latch member pivoted a fined point e ctive to restrainarm against such electro-responsive means for trippin said latch andmaintaining the same ineneetive during overloads, and actuating meansoperable to move said lever and jointly in either direction during r ofthe latter cy said latch d. In a circuit breaker, in combination apivotally mounted lever, a switch arm mou ted thereon for joint movementtherewith and movement relative thereto, a latch member pivoted at a 1red point and adapted to gage an extension of said arm forrestrainingthe same against such independent movement,electro-responsive means for rendering said member ineffective duringoverloads, and actuating means for said lever operable upon release ofsaid arm by said latch to restore the former to position suitable forengagement by the latter.

5. in a circuit breaker, in combination, a pivotally mounted lever, aswitch arm mounted thereon for joint movement therewith and movementrelative thereto, a latch member pivoted at a fixed point and adapted toengage an extension of said arm for restraining the same against suchindependent movement, electro-responsive means for rendering said memberineffective during overloads, and actuating means for said leveroperable upon release of said am by said latch to restore the former toposition suitable for engagement by the latter and during suchengagement to move said lever and said arm jointly in either direction.

6. In a circuit breaker, in combination, a pivotally mounted lever, aswitch arm mounted thereon and movable therewith to closed circuitposition said arm being movable independently of said lever to opencircuit position, a latch pivoted at a fixed point'ior restraining saidarm against said latter movement and electro-responsive means fortripping said lat-ch upon over- I support and said arm havingcooperating parts for limiting such movement, means for normallyrestraining said arm against such movement, operating means for movingsaid lever and said arm jointly to closed circuit position duringrestraint of the former by said restraining means, andelectro-responsive' means efiective upon overload to release said armfrom said restraining means for movement 0r said arm to open circuitposition and for rendering said operating means inen' ective to movesaid arm to closed circuit position prior to reengagement of saidrestraining means.

8. In a circuit breaker, in combination, a lined support, a leverpivoted medially upon said lever and biased to move relatively theretoto open circuit position, a roller carried by said arm and adapted toengage a stop ca rried by said support for limiting such movement, alatch member pivoted upon said support for normally restraining said armagainst such movement,

operating means for moving said arm and. said lever jointly to circuitcloslng or circuit thereon, a switch arm pivotally mounted

